History and Perspectives of Nuclear Medicine in Thailand.

In 1955, the first nuclear medicine division was established in Thailand by Professor Romsai Suwannik in the Department of Radiology, Siriraj Hospil, Mahidol University in Bangkok. In 1959 four years later, the second nuclear medicine division was established in the Department of Radiology, Chulalongkorn Hospital in Bangkok. The third nuclear medicine division was started in Rajvithi Hospital in Bangkok in 1961. The fourth nuclear medicine division was installed in Chiang Mai University which is the first University located outside of Bangkok in 1965 by Professor Dusadee Prabhasavat and Professor Sanan Simarak, ten years after the first nuclear medicine division in Siriraj Hospital. At the present in Thailand, there are twenty-five organizations providing clinical nuclear medicine services. Five medical faculties provide three years nuclear medicine residency training. There are eight companies which supply radiopharmaceuticals and/or nuclear medicine instruments one of these belongs to governmental office of atomic for peace (OAP of Thailand). In conclusion: Nuclear medicine researches and clinical practices in Thailand had been progressed from the past to the present time and will more progress in the near future, which certainly is the part of Asian countries and ARCCNM.

In 1955, the first nuclear medicine division was established in Thailand by Professor Romsai Suwannik at the Department of Radiology of Siriraj Hospital, Mahidol University in Bangkok. Four years later in 1959, the second nuclear medicine division was established at the Department of Radiology of Chulalongkorn Hospital in Bangkok, and the third division was founded at Rajavithi Hospital in Bangkok in 1961. In 1965, ten years after the establishment of the first nuclear medicine division in the country, Professor Dusadee Prabhasavat and Professor Sanan Simarak established the fourth nuclear medicine division at Chiang Mai University, which is the first university located outside Bangkok.
During the early years of nuclear medicine in Thailand (1955)(1956)(1957)(1958)(1959)(1960)(1961)(1962)(1963)(1964)(1965), Professor Romsri Suwannik at Siriraj Hospital applied clinical nuclear medicine by using colloidal gold ( 198 Au) for palliative treatment of ascites, caused by ovarian cancer. In vivo radionuclide non-imaging studies mostly focused on 131 I thyroid uptake, extracellular fluid volume ( 82 Br-distribution space), and exchangeable 24 Na. 42 K was studied in cholera patients, and 32 P was used for radionuclide therapy in malignant pleural effusion and some blood diseases, e.g., leukemia and polycythemia vera. 32 P was also used for differential diagnosis of benign and malignant pleural effusions.
Since 1965, many radionuclide non-imaging studies have been performed including blood volume studies, 51 Cr red blood cell (RBC) survival and ferrokinetic studies with 59 Fe, 51 Cr platelet survival and kinetic studies with 125 I-labeled fibrinogen, and 55 Fe and 59 Fe absorption studies. Evaluations of renal tubular function using 131 I-hippuran and renal glomerular function using 99m Tc-DTPA are also included in routine clinical services.
For radionuclide imaging studies, 113m Ingenerator and 198 Au were used in early years before 99m Tc generators became available. In 1969, the first radioimmunoassay laboratory was established for clinical services. Also, since 1983, neonatal screening for congenital hypothyroidism has been performed using nuclear medicine techniques in Thailand.
Professor Romsai Suwannik made tremendous efforts for the progress of nuclear medicine in Thailand. One of his well-known studies in nuclear medicine was about thyroid disease in Thailand (Figure 1). He introduced the addition of iodine into drinking water for people living in the Northern and Northeastern parts of the country, which are the endemic areas of goiter in Thailand. He is also known as the father of nuclear medicine in Thailand, and was awarded the medal of Chevalier de l'Ordre du Mérite ( Figure 2).
Nuclear Medicine Society of Thailand was established in 1982 with 120 members, and Professor Romsai Suwannik was elected as the first president. At present, this organization consists of 227 members, including 78 nuclear medicine physicians.
Many nuclear medicine personnel have made great contributions to the progress of nuclear medicine services in Thailand. Professor Vichai Poshyachinda, who worked during the early years of nuclear medicine in Thailand,     Radiologists of Thailand, and the other is midyear nuclear medicine academic meeting, which is held by the Nuclear Medicine Society of Thailand. At these two meetings, the findings of nuclear medicine studies of all related institutes are presented. Also, several lectures are presented by nuclear medicine professors from other countries at these meetings each year.
In Thailand, we also have the opportunity to annually organize international academic meetings including IAEA and The Asian Regional Cooperative Council for Nuclear Medicine (ARCCNM) meetings (Figures 6 & 7).

Conclusion
Nuclear medicine research and clinical practice in Thailand have greatly improved in recent years and will experience more progress in near future. These achievements contribute to the progress of ARCCNM and Asian countries in this scientific field.